Allentown detectives released a surveillance video Tuesday that they hope will lead to some clues into the slaying of a 57-year-old man found shot to death on the porch of his West End home three years ago.

The police department's cold case unit posted the video, recovered just hours after Rocco P. Marinaro was killed March 12, 2012, to its website. The video, police said, has not been released previously.

It can be viewed on The Morning Call website.

In the video, two men can be seen at 19th and Allen streets moments before Marinaro is shot, police Assistant Chief William Lake said Tuesday. Two men in dark clothing and baseball caps approach the street corner and one enters a building below a traffic light, while another appears to be smoking a cigarette and stops at the corner for a moment during the nine-second clip.

"We are hopeful that someone recognizes one or both of these men or that one of these men come forward as they may have more information," Lake said.

Marinaro, 57, of 1942 Allen Street was found shot to death on the enclosed porch of his row home March 14, 2012. He was found lying in the porch doorway and police suspect he may have been shot two days before his body was found.

Police had been called to the neighborhood about 8:40 p.m. two days before on a report of shots fired, but didn't find any evidence of a shooting at the time.

Marinaro was a manager of environmental compliance at Keystone Cement. He had not been to work the previous two days.